libNUI is a hardware accelerated GUI framework that makes it possible to build rich multi-platform applications based on 3D rendered dynamic layouts. Interfaces are built as a composition of widgets and behaviors, and the framework handles positioning, resizing, anchoring, and texture stretching. Objects are connected with synchronous events and delegates for mono-threaded communication, or asynchronous notifications and message queues are used for multi-threaded applications. It also supports strings (including Unicode), paths, files, data streams, fonts, threads, critical sections, audio buffer rendering, and more.

footware is a tiny program that lets you use a MIDI-input device as a PC-keyboard extension. For example, the author uses a 10-key foot-controller (hence the name "footware") to send keypress events like "esc", "shift", "ctrl", "end", and "alt".

wumwum is a window manager manager. The idea behind wumwum is to turn any EWMH-compliant window manager into a tiling manager a la "ion" or "awesome". wumwum works by using wmctrl, and adapts itself dynamically to the active window manager. All functionality from the underlying window manager is kept when under wumwum, making it ideal for beginners.

The aim of LucED is to be a fast and responsive X11 text editor with a simple but powerful user interface similar to NEdit. It uses Lua as an embedded scripting language, and features syntax highlighting that is configurable via PCRE regular expressions with arbitrarily nested patterns.

Disko is a user interface application framework for the fast and simple development of flexible applications on embedded Linux systems, with a particular focus on interactive user interfaces. It is high-performance and easy to learn, and due to its architecture is well suited to creating complex applications.

Xnee can record, distribute, and replay X (X11) protocol data. This
is useful for automated tests of applications or benchmarking of
applications. Think of it as a robot. A GUI, a Gnome Panel Applet, and a
CLI are available, as well as bash functions.

Lunchbox is a dynamic tiling window manager for X11. It allows windows to be resized by squishing them against the edge of the screen. In a step away from the desktop metaphor, all programs are given a separate workspace and unique arrangement of windows, and any window can become the desktop. It offers an in-built scalable tab replacement called the Title Menu, which allows any window to be swapped with any other window that fits, allowing very fine grained control over the layout of the screen. Finally, although many windows default to tiling, any window can be changed to a Floating mode, which dialog boxes default to.